▎ 摘　　要

Copper nanoparticles modified nitrogen doped reduced graphene oxide 3-D superstructure was successively prepared via a two-step reaction. Polydopamine was used as nitrogen source for the fabrication of nitrogen doped reduced graphene oxide and reducing agent for in-situ reduction of CuCl2. After calcination under nitrogen protection, the conductivity, electron transfer ability and electrocatalytic activity of nanocomposites were substantially improved. The enhanced redox property could be attributed to the difference in the electronegativity of carbon and nitrogen atoms of the 3-D superstructure. By using this composite material, an electrochemical sensor was constructed for the detection of dihydroxybenzene isomers, which exhibited excellent sensitivity (with limit of detection at 81-131 nmol L-1 levels), wide linear ranges (0.5-720 mu mol L-1) and good selectivity. Hence it was directly applied for the simultaneous determination of dihydroxybenzene isomers in contaminated samples (e.g., waste waters). (C) 2017 Elsevier B.V. All rights reserved.